Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é a rodada para o UFC no Fox: evento Velasquez vs. Dos Santos?
 ###Tabelas: CREATE TABLE kwai_tsing_container_terminals (kwai_tsing_container_terminals_id AUTO_INCREMENT PRIMARY KEY, Terminal VARCHAR, Operator VARCHAR, Depth (m) VARCHAR, Berths INT, Quay cranes INT) CREATE TABLE mixed_martial_arts_record (mixed_martial_arts_record_id AUTO_INCREMENT PRIMARY KEY, Res. VARCHAR, Record VARCHAR, Opponent VARCHAR, Method VARCHAR, Event VARCHAR, Round INT, Time VARCHAR, Location VARCHAR) CREATE TABLE awards_ceremonies (awards_ceremonies_id AUTO_INCREMENT PRIMARY KEY, Ceremony VARCHAR, Date VARCHAR, Host(s) VARCHAR, Venue VARCHAR, Film of the Year VARCHAR) CREATE TABLE composition_of_the_5th_seanad (composition_of_the_5th_seanad_id AUTO_INCREMENT PRIMARY KEY, Administrative Panel INT, Agricultural Panel INT, Cultural and Educational Panel INT, Industrial and Commercial Panel INT, Labour Panel INT, National University of Ireland INT, University of Dublin INT, Nominated by the Taoiseach INT, Total INT) CREATE TABLE 2013_draft_picks (2013_draft_picks_id AUTO_INCREMENT PRIMARY KEY, Round INT, Overall VARCHAR, Player VARCHAR, Position VARCHAR, Nationality VARCHAR, Club team VARCHAR)  
SELECT AVG Round FROM mixed_martial_arts_record WHERE Event = ufc on fox: velasquez vs. dos santos